package network.udp;

import java.io.IOException;
import java.net.*;
import java.util.Scanner;

//回显客户端
public class UdpEchoClient {
    private DatagramSocket socket = null;
    private String serverIp;
    private int serverPort;

    public UdpEchoClient(String serverIp,int serverPort) throws SocketException {
        this.serverIp=serverIp;
        this.serverPort=serverPort;
        socket = new DatagramSocket();

    }
    public void start() throws IOException {
        System.out.println("客户端启动");//元神启动
        Scanner scanner = new Scanner(System.in);
        while (true){
            //1.从控制台读取发送的请求数据
            System.out.print("-> ");//提示用户接下来要做的事
            if (!scanner.hasNext()){//4.进入阻塞
                break;
            }
            String request = scanner.next();
            //2.构造请求并发送
            DatagramPacket requestPacket = new DatagramPacket(request.getBytes(),
                    request.getBytes().length,InetAddress.getByName(serverIp),serverPort);
            socket.send(requestPacket);//5.发送
            //3.读取服务器的响应
            DatagramPacket responsePacket = new DatagramPacket(new byte[4096],4096);
            socket.receive(responsePacket);//6.进行阻塞
            //4.把响应显示到控制台上
            String response = new String(responsePacket.getData(),0,responsePacket.getLength());
            System.out.println(response);
        }
    }

    public static void main(String[] args) throws IOException {
        UdpEchoClient client = new UdpEchoClient("127.0.0.1",9090);
        client.start();//2.服务器启动
    }

}
